I think Hong Kong has handled it well so far, given that they had limited options in terms of where Marvel could go (you had Fantasyland or Tomorrowland as the only truly viable options since they nixed the second gate), and I think the Stark Expo is about as good of a tie in as one could think of. It at least gives a viable reason for Tony to be there, and the faux-World's Fair idea is a throwback to Disney's history of taking World's Fair attractions and putting them in their theme parks. What I'm interested to see is how they handle the upcoming attractions. Why is there a SHIELD base in Tomorrowland? What's the reasoning for the Buzz replacement to be there?
They'll have to be careful if they want to maintain the level of plausibility that they've established with Iron Man, which I can't knock them for, given their efforts to make it blend in (I know the original intent was to have an alien spaceport, but they broke that rule almost immediately anyway). It certainly comes across as more careful than their stateside efforts regarding the same properties.